Cysteamine eye drops in the treatment of cystinosis – an Australian perspective

Abstract

AbstractCystinosis is a rare but very serious genetic disorder. Advancements in medical science, in the past few decades, have transformed this previously terminal condition into a manageable disease. Ophthalmic sequelae of cystinosis are caused by accumulation of cystine crystals in ocular tissues and are very troublesome for most cystinosis patients. Accumulation of crystals in the cornea causes debilitating photophobia and pain that does not respond to systemic cysteamine therapy. If left untreated, this can lead to structural damage (corneal ulcers, scarring and band keratopathy) and eventually result in corneal blindness requiring corneal transplant. Topical ophthalmic application of cysteamine can alleviate the symptoms and, if instituted early, may prevent the damage. There is no commercially manufactured ophthalmic cysteamine product available in Australia and patients who receive treatment are usually supplied with extemporaneously prepared cysteamine eye drops or ointment. Stability issues, various factors influencing product effectiveness and patient adherence are only few of the problems that make formulation and compounding of cysteamine ophthalmic products a complex task.